A Sampler for Respiratory Health Hazard Assessment

A multistage-multijet air sampler is described which automatically classifies air-borne particles according to their aerodynamic dimension, which is the only true measure of lung penetrability. The standard instrument, with six 400-jet stages, has been calibrated with unit density spheres with respect to the particle sizes collected on each stage. Since “the selective action of the respiratory system in dealing with dust particles of different aerodynamic sizes is well known,” assessments of the health hazard of any sample can be made with the instrument. The small jets make possible the collection of particles at lower jet velocities, on uncoated plates, with sharper particle size discrimination.